SEARCH

SEARCH BY CITATION

Keywords:

  • Quality of life;
  • Pediatric scale;
  • Systemic lupus erythematosus;
  • Simple Measure of Impact of Lupus Erythematosus in Youngsters

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

Objective

Pediatric systemic lupus erythematosus (SLE) is a chronic fluctuating disease that significantly impacts quality of life (QOL). There is no pediatric SLE-specific health-related QOL (HRQOL) scale. Our objective was to develop and validate a new pediatric SLE-specific HRQOL scale.

Methods

We developed the Simple Measure of the Impact of Lupus Erythematosus in Youngsters (SMILEY) based on results of qualitative research of children with SLE and their parents. SMILEY has parallel child and parent reports with a 5-faces scale for responses. SMILEY comprises 4 domains: effect on self, limitations, social, and burden of SLE. In this cross-sectional study, we examined face, content, construct, and concurrent validity; internal consistency; test–retest reliability; and child-parent agreement for SMILEY. Children ≤18 years of age with SLE and their parents completed corresponding child and parent SMILEY reports, as well as other QOL and physical function scales. Qualified physicians assessed SLE activity, damage, and severity.

Results

Eighty-six children with SLE and 80 parents participated. SMILEY was found to have face, content, construct, and concurrent validity (Spearman's rank correlation [rs] ≥0.4); test–retest reliability (intraclass correlation coefficient [ICC] 0.9); and internal consistency (α = 0.9). Moderate agreement was found between child and parent SMILEY reports (ICC 0.7, rs = 0.5, P < 0.001).

Conclusion

SMILEY is a brief, easily understood, valid, and reliable pediatric SLE-specific QOL scale. Because SMILEY assesses children's self-perception of QOL as impacted by SLE, we predict that it will have great utility in clinical practice, clinical trials, and outcomes research.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

In children, systemic lupus erythematosus (SLE) is associated with significant morbidity consequent to the disease and its treatment, and comprises a wide-ranging spectrum of physical, functional, and psychological damage that impacts quality of life (QOL). Growth failure and delayed puberty are unique concerns in pediatric SLE (1). Health-related QOL (HRQOL) is an integral component of the core outcome measures for the evaluation of treatment response in juvenile SLE (2), but there is currently no SLE-specific pediatric QOL scale. The chronic, episodic, and unpredictable course; heterogeneity within and between patients; evolving needs, expectations, and cognitive development of children; use of proxy respondents; and complex psychosocial factors in SLE complicate QOL measurement (3–5). Most HRQOL questionnaires were not developed specifically for children with SLE and therefore present different limiting features when considered in the context of pediatric SLE (4, 5). First, several QOL instruments used in children with rheumatic diseases are heavily weighted to detect the impact of arthritis, which is often not the single major issue in children with SLE. Second, generic QOL scales may not adequately capture all the relevant domains in pediatric SLE unless used in conjunction with other more specific measures. Third, not all the instruments are valid, reliable, have parallel child and parent reports, and have age-adjusted formats to account for children's developmental stages that affect cognitive function, autonomy, body image, and recall (6).

We considered several aspects of questionnaire development while designing a pediatric SLE-specific QOL scale. An adequate measure should preferably be derived from patients' attitudes and expectations. It should be brief, be easy to administer, complete, and score, and include parallel child and parent reports with language-adjusted formats for different age groups that consider children's changing cognitive skills (7). The measure should be valid and reliable across a wide age range to facilitate clinical comparisons and long-term prospective outcome studies in this population (8). To maximize the generalizability and relevance of the measure, self-concept and missed school days need to be considered (9, 10). This is the first report of the development and validation of a new SLE-specific QOL instrument.

SUBJECTS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

Subjects and settings.

Children ≤18 years of age diagnosed with SLE, followed for at least 1 month, and able to participate in the study as determined by the pediatric rheumatologist, and their parents (or legal guardians) were recruited from 6 US pediatric rheumatology practices. Pediatric rheumatology centers that followed children with SLE in their inpatient and outpatient facilities and had the necessary resources to adhere to our protocol were selected. The 6 practices were the University of Medicine and Dentistry of New Jersey/Robert Wood Johnson Medical School, New Brunswick, New Jersey; Hospital for Special Surgery, New York, New York; St. Barnabas Pediatric Subspecialty Center, Livingston, New Jersey; Hackensack University Medical Center, Hackensack, New Jersey; La Rabida Children's Hospital, Chicago, Illinois; and Cleveland Clinic Foundation, Cleveland, Ohio. Inclusion from different centers facilitated examination of children across a broad range of ages, ethnicities, socioeconomic status, disease activity, and damage so that our results had considerable generalizability. Subjects were required to understand English. Children were excluded if they were unable to complete the questionnaires or had a significant comorbid condition exclusive of SLE that was likely to impact QOL.

Measures.

The Simple Measure of Impact of Lupus in Youngsters (SMILEY; copyright L. Nandini Moorthy, MD, MS) conceptualizes QOL as the children's and parents' perceptions of the impact of SLE on different aspects of children's lives. The content of SMILEY was derived to reflect QOL issues in juvenile SLE in clinical practice and domains of relevant pediatric QOL/HRQOL instruments. The initial version (11) was modified with qualitative research in children with SLE and their parents (12). To ensure content validity, categories derived from the qualitative responses were modified into domains. The 31-item SMILEY (version 2) is a brief, easily understood, and valid pediatric SLE-specific QOL scale (13, 14). Pediatric rheumatologists; expert(s) in research methodology, health behavior, and biostatistics; research assistants; and children with SLE and their parents reviewed the questionnaire at different stages of its development. Intraclass correlation coefficients (ICCs) were calculated to examine questions for redundancy. We deleted 5 questions due to perceived lack of relevance, redundancy, and some ambiguity in the potential interpretation of the question and/or the response.

The final 26-item SMILEY (version 3) for children with SLE ages <19 years features parallel child self-reports and parent reports with responses in the form of a 5-step scale with different facial expressions (Appendix A, available at the Arthritis Care & Research Web site at http://www.interscience.wiley.com/jpages/0004-3591:1/suppmat/index.html). This pictorial format allows easy comprehension across different ages and cultures. The 4 domains are effect on self (5 items), limitations (8 items), social (4 items), and burden of SLE (7 items). Items related to school are spread across all domains. The reading level for SMILEY is fifth grade. Each item score ranges from 1 to 5 and the total score is transformed to a 1–100 scale. Higher scores indicate better QOL. If >12 questions are not answered, the SMILEY cannot be scored. The first 2 items on current SLE status and QOL assessment are not included in the domains or in calculating the final score. The remaining questions refer the respondent to the previous month.

Additional scales.

PedsQL Generic 4.0 and Rheumatology 3.0 modules child and parent reports.

The child and parent reports of the Pediatric Quality of Life (PedsQL) Generic 4.0 and PedsQL Rheumatology 3.0 modules are QOL scales used in children with rheumatic diseases (7, 15). The Generic module has physical, emotional, social, and school domains. Scores are calculated on a 0–100 scale, with higher scores representing better QOL (16). For the Rheumatology module, only the domain scores (pain and hurt, daily activities, treatment, worry, communication), not the total score, are reported (15).

Childhood Health Assessment Questionnaire.

The Childhood Health Assessment Questionnaire (C-HAQ) with child and parent reports estimates physical function in children 2–19 years of age with rheumatic diseases (17, 18). Higher scores represent greater disability.

Piers-Harris Self concept scale.

The Piers-Harris Self Concept Scale (SCS), entitled “The Way I Feel About Myself,” consists of 80 questions pertaining to 6 domains relating to children's attitudes about themselves: behavior, anxiety, physical appearance, popularity, happiness/satisfaction, and school. Average scores usually range from 46 to 60, with higher scores corresponding to better self-concept (19, 20).

SLE Disease Activity Index and the Physician's Global Assessment.

The SLE Disease Activity Index (SLEDAI) and the Physician's Global Assessment (PGA) are measures of SLE disease activity (21, 22). The PGA Likert scale categorizes patients into graded stages of none, mild, moderate, or severe disease activity.

Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

The Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) measures irreversible functional changes at the level of specific organs in persons with SLE (23–25).

Additional data collected included child's date of birth, age, sex, ethnicity, comorbidity, insurance, education, and impact of disease on child's and parent's lives, using the PedsQL family information form and additional survey questionnaires developed during this study (15). We recorded the date of disease onset and use of all medication(s), including current and prior use of corticosteroids and immunomodulating drugs.

Procedure.

Appropriate institutional review board approval was obtained at all sites. Potential subjects were identified at each center through the clinic appointment schedule or during inpatient admissions. Children and parents completed corresponding versions of the 26-item SMILEY, PedsQL Generic and Rheumatology modules, and C-HAQ. Children also completed the SCS. Questionnaire completion took ∼30 minutes. Children completed questionnaires independent of their parents. The investigator was available at all times to respond to queries posed by study respondents. The examining physicians completed the SLEDAI, PGA, and SDI for each subject at the time of the study interview. We maintained a screening log of subjects who refused to participate in order to assess generalizability of our results.

To evaluate test–retest reliability, children and parents were given a duplicate copy of the SMILEY, which was completed within 10 days of the initial administration and returned by mail in a stamped, self-addressed envelope provided by the investigators. For instances in which we did not receive the questionnaires in a timely manner, we repeated the above procedure of 2 SMILEY administrations within 10 days. We chose 10 days for this assessment because the SLEDAI uses 10 days as the interval for evaluating disease activity (22). We assessed child and parent reports of perceived SLE status and global QOL at baseline and at the time of test–retest reliability analysis to ensure that the measurement of test–retest reliability was valid.

Methods and statistical analysis.

Using the SPSS statistical package for Windows, versions 13 and 14 (SPSS, Chicago, IL), initial descriptive analyses were performed on all variables. Individual instrument scores were examined for ceiling and floor effects. All variables were examined to ascertain the data distributions and assess normality. Spearman's rank correlations were used to determine relationships between scores of various instruments. A record of eligible subjects who had not completed parts of the questionnaires was generated. Minimal missing data were handled in accordance with rules for scoring each questionnaire. Feasibility was determined from the percentage of missing values for each item and the distribution of item responses (16). All analyses were performed separately for child and parent SMILEY reports. The following steps were performed for both child and parent SMILEY reports to determine the psychometric properties.

To determine face validity, research assistants, members of the research team, and subjects (children with SLE and their parents) were asked to provide feedback regarding relevance, completeness, and comprehension of SMILEY. Internal consistency was determined by calculating Cronbach's alpha for SMILEY domain and total scores. Test–retest reliability was assessed using ICC (absolute agreement reliability analysis) and Spearman's correlation rho between scores at baseline and at the time of reliability analysis. Agreement between SMILEY child and parent report total and domain scores was determined using Spearman's rho and ICC. Concurrent validity was determined by examining Spearman's correlations between SMILEY child and parent reports with corresponding versions of the PedsQL Generic and Rheumatology modules and the C-HAQ. We hypothesized that children with higher QOL as measured by SMILEY scores will also have higher QOL as assessed by the PedsQL and better physical function as determined by the C-HAQ. Construct validity was assessed through Spearman's correlations of SMILEY with estimates of morbidity and illness burden, measures of self-esteem, and global QOL (16). We hypothesized the following: 1) higher SMILEY score would be associated with fewer days of the child needing care for a physical/mental health condition, fewer days missed from school for children and work for parents, and less impact on work routine and concentration for parents; 2) significant correlations would be seen between the child SMILEY report and self-concept scale scores; and 3) subject's perception of QOL and global SLE status would correlate significantly with total and domain SMILEY scores.

Discriminant (divergent) validity (26) was determined with Spearman's correlations between SMILEY and disease duration, SLEDAI, PGA, and SDI. We hypothesized that only mild or moderate correlations would be found. Although increased disease activity and damage would impact QOL, they are not sole determinants of QOL and therefore should be considered collectively to obtain a comprehensive evaluation (9, 27–29).

Discriminative validity was calculated using the extreme groups method (26). Comparisons were performed between mean SMILEY scores of subjects with low and high disease severity, activity (PGA cutoff 2, SLEDAI cutoff >12) (30), and damage (SDI cutoff 2) (25). Current or prior use of immunomodulating medication was used to measure SLE severity. Immunomodulating agents included cyclophosphamide, rituximab, azathioprine, thalidomide, mycophenolate mofetil, methotrexate, cyclosporin, tacrolimus, and intravenous immunoglobulin (IVIG). Although hydroxychloroquine is a steroid-sparing agent and used in patients with SLE, we did not include it in the definition of immunomodulating agents. Children with prior use of immunomodulating agents often have greater morbidity, due to greater disease severity and treatment effects, that impacts their QOL. However, some patients may have improved significantly after a course of immunotherapy, and therefore we conducted additional analyses in children currently receiving medications versus those who had never used them.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

Eighty-six children with SLE with well-distributed ethnicity (36% African American, 17% Asian, 28% Mexican/Latino, 17% white) and insurance coverage participated in the study. Seventy-one (83%) were female with a mean age of 15 years (range 7–18 years), mean education of 9 years (current education or highest year completed), and mean ± SD self-concept scores of 50 ± 16 (n = 81) (Figure 1). The median duration of SLE was 24 months (range 1–84 months), median SLEDAI score was 4 (range 0–23), and median SDI score was 1 (range 0–10, n = 70) (Figure 1). Because 16 of 86 patients had SLE duration of less than 6 months at the time of enrollment, we did not report their SDI scores. PGA-rated disease activity was as follows: none (9%), mild (48%), moderate (37%), and severe (6%). Most subjects were either currently receiving or had previously received steroids (97%) and at least 1 immunomodulating agent (76%), the most common being cyclophosphamide (49%). Other immunomodulating medications ever taken (current and prior use) were rituximab (n = 6 [7%]), thalidomide (n = 4 [5%]), methotrexate (n = 11 [13%]), azathioprine (n = 17 [20%]), mycophenolate mofetil (n = 28 [33%]), cyclosporin (n = 4 [5%]), and IVIG (n = 3 [4%]). Other medications ever used were hydroxychloroquine (n = 55 [68%]), dapsone (n = 1 [1%]), and etanercept (n = 1 [1%]). Eighty-one parents participated and most were mothers (n = 61).

thumbnail image

Figure 1. Error bars with mean ± 2 SDs of the following variables: Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), Physician's Global Assessment (PGA), Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), SLE duration, age of children, education, child and parent Simple Measure of the Impact of Lupus Erythematosus in Youngsters (SMILEY) total and domain scores, and the self-concept scale scores.

Download figure to PowerPoint

Feasibility.

Eighty-six children and 80 parents completed the corresponding SMILEY reports. Subjects completed SMILEY in <10 minutes and scoring each questionnaire took ≤10 minutes. For the child SMILEY report, 15 items were omitted out of a total of 2,236 items (26 items × 86 children), with a mean ± SD number of items omitted of 0.2 ± 0.6. The maximum number omitted was 5 items by one child. For the parent SMILEY report, 44 items were omitted out of a total of 2,080 items (26 items × 80 parents). The mean ± SD number of items omitted was 0.6 ± 1. The maximum number omitted was 10 items by one parent.

Means, SDs, and response range of SMILEY and other questionnaires.

Scores and distribution of the SMILEY, C-HAQ, and PedsQL Generic and Rheumatology modules are provided in Table 1 and Figure 1.

Table 1. Scale descriptives for child and parent reports of measures*
QuestionnaireChild reportParent report
  • *

    Values are the total number; mean ± SD (range) or total number; mean ± SD. PedsQL Generic module total and subscale scores, PedsQL Rheumatology module subscale scores, and SMILEY version 3 (final version) scores range 0–100; C-HAQ scores range 0–3 with mode of 0 for child and parent reports. SMILEY = Simple Measure of the Impact of Lupus Erythematosus in Youngsters; SLE = systemic lupus erythematosus; QOL = quality of life; C-HAQ = Childhood Health Assessment Questionnaire; PedsQL = Pediatric Quality of Life Inventory.

  • Psychosocial score is the mean of scores from the social, emotional, and school domains.

SMILEY total86; 65 ± 13 (37–93)80; 62 ± 16 (28–98)
 Effect on self85; 65 ± 17 (24–100)79; 59 ± 17 (24–100)
 Limitations86; 63 ± 17 (25–95)80; 60 ± 18 (25–100)
 Effect on social life86; 81 ± 17 (35–100)80; 74 ± 17 (35–100)
 Burden of SLE86; 57 ± 16 (23–97)79; 56 ± 17 (20–100)
 Global QOL84; 82 ± 18 (20–100)78; 73 ± 20 (40–100)
 SLE status85; 77 ± 20 (40–100)78; 72 ± 21 (20–100)
C-HAQ disability index86; 0.3 ± 0.4 (0–3)79; 0.3 ± 0.6 (0–3)
PedsQL Generic total86; 72 ± 1777; 64 ± 21
 Physical86; 70 ± 2078; 62 ± 26
 Mean psychosocial86; 72 ± 1877; 65 ± 21
PedsQL Rheumatology  
 Daily activities85; 91 ± 1477; 85 ± 20
 Treatment85; 81 ± 1978; 73 ± 23
 Pain and hurt85; 72 ± 2478; 63 ± 28
 Communication85; 70 ± 2378; 73 ± 27
 Worry85; 55 ± 2877; 57 ± 32

Face validity.

All the reviewers of SMILEY found it to be valid, relevant, and easy to understand, and especially liked the responses in the form of faces.

Internal consistency.

Cronbach's alphas for the child report of SMILEY total and domain scores were as follows: 0.9 for total, 0.8 for effect on self, 0.8 for limitations, 0.7 for social, and 0.8 for burden of SLE. Cronbach's alphas for the parent report of SMILEY total and domain scores were as follows: 0.9 for total, 0.9 for effect on self, 0.9 for limitations, 0.6 for social, and 0.9 for burden of SLE.

Test–retest reliability.

Thirty-eight children (44% response rate) and 32 parents returned the SMILEY after a mean ± SD of 14 ± 11 days (median 10 days). The mean ± SD child SMILEY total score was 67 ± 13 at baseline and 68 ± 16 at the time of reliability analysis. Mean parent SMILEY total score was 66 ± 13 at baseline and 65 ± 17 during reliability analysis. The perceived SLE status scores (median 80) and global QOL status scores (median 80) were constant at baseline and at the time of test–retest reliability analysis for child and parent reports, thus confirming the measurement of test–retest reliability. The ICC (0.7–0.9, P < 0.001) and rho (0.6–0.9, P < 0.001) for the total and domain scores were high for both child and parent reports.

Agreement between child and parent SMILEY reports.

For the available child-parent pairs (n = 80), moderate rho (0.4–0.6, P < 0.001) and ICC (0.6–0.7, P < 0.001) values were seen between the child and parent SMILEY total and domain scores.

Concurrent validity.

Significant correlations (rs ≥ 0.4) were seen between child and parent SMILEY total scores and corresponding reports of the C-HAQ, PedsQL Generic, and PedsQL Rheumatology modules (Table 2).

Table 2. Spearman's rank correlation (rs) of SMILEY with corresponding versions of standard instruments*
Standard scalesSMILEY child, rs (no.)SMILEY parent, rs (no.)
  • *

    See Table 1 for definitions. P ≤ 0.001 for all values.

C-HAQ disability index0.6 (86)0.5 (77)
Global QOL0.5 (84)0.6 (78)
PedsQL Generic total0.6 (86)0.6 (76)
 Physical0.6 (86)0.5 (77)
 Emotional0.5 (86)0.6 (75)
 Social0.5 (86)0.6 (76)
 School0.4 (86)0.5 (75)
PedsQL Rheumatology  
 Pain/hurt0.5 (85)0.5 (77)
 Daily activities0.4 (85)0.4 (76)
 Treatment0.5 (85)0.6 (77)
 Worry0.6 (85)0.5 (76)
 Communication0.5 (85)0.5 (77)

Construct validity.

Significant Spearman's correlations were seen between SMILEY total scores and the variables associated with morbidity, self-concept scale, global QOL, and SLE status (Table 3).

Table 3. Construct validity of child and parent SMILEY reports*
Impact of disease and self-conceptSpearman's correlations
rsPNo.
  • *

    Items 1–6 are from the impact scale of the PedsQL family information form, which is generally completed by the parents, and pertain to the impact of the child's physical or mental health in the last 30 days. See Table 1 for definitions.

  • Some subjects filled out numbers ≥30. Because there are only 20 school days a month, we corrected any value >20 to 20.

  • Some subjects filled out numbers ≥30. Because there are only 31 or 30 days a month, we corrected any value >30 to 30.

1. Days of school child missed   
Child0.30.00672
Parent0.30.00568
2. Days child was sick in bed or too ill to play   
Child0.40.00174
Parent0.40.00169
3. Days child needed someone to care for him/her   
Child0.40.00171
Parent0.50.00166
4. Days parent missed work   
Parent0.20.245
5. Interfered with parent's daily routine at work   
Parent0.40.00756
6. Interfered with parent's ability to concentrate at work   
Parent0.50.00156
7. Self-concept scale total score   
Child0.50.00181
8. Self-perceived global QOL of child   
Child0.50.0184
Parent0.60.0178
9. Self-perceived global SLE status of child   
Child0.60.0185
Parent0.50.0178
Discriminant validity.

The child SMILEY limitation domain (n = 86) correlated mildly with the PGA (rs = 0.3, P = 0.02), SLEDAI total score (rs = 0.2, P = 0.02), and SDI (rs = 0.2, P = 0.03). Total/domain scores of child/parent SMILEY did not correlate significantly with SLEDAI, PGA, SDI, or disease duration.

Discriminative validity.

SMILEY total and domain scores were higher indicating better QOL in children with lower disease activity, lower damage, and in those who had never used immunomodulating agents. The trend was most marked in the limitation domain (Table 4).

Table 4. Discriminative validity of SMILEY*
SLE-related variablesLimitations domain of SMILEY
ChildParent
  • *

    Values are the mean ± SD (number). Independent sample t-test was conducted on the mean limitation domain SMILEY scores. The grouping variables are listed under the SLE-related variables columns. SLEDAI = Systemic Lupus Erythematosus Disease Activity Index; PGA = Physician's Global Assessment; SDI = Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index; see Table 1 for additional definitions.

  • P ≤ 0.05 (comparison of means by independent sample t-test; equal variances not assumed). Significant P values were calculated for child SMILEY limitation domain score comparison of means for PGA >2 versus <2; SDI >2 versus ≤2; cyclophosphamide current use versus never used; immunomodulating therapy current use versus never used; and immunomodulating therapy ever used versus never used. Significant P values were obtained for the parent SMILEY total score comparison of means for immunomodulating therapy current use versus never used and immunomodulating therapy ever used versus never used (data not shown).

SLEDAI  
 Score >1255 ± 16 (10)57 ± 21 (10)
 Score ≤1265 ± 17 (76)61 ± 18 (70)
PGA  
 Score ≥259 ± 13 (37)57 ± 17 (34)
 Score <267 ± 19 (49)63 ± 18 (46)
SDI  
 Score >255 ± 13 (14)56 ± 16 (13)
 Score ≤266 ± 18 (56)59 ± 17 (51)
Cyclophosphamide  
 Current use57 ± 19 (21)55 ± 17 (20)
 Never used67 ± 16 (44)63 ± 19 (41)
 Discontinued62 ± 15 (21)59 ± 17 (19)
Immunomodulating agent  
 Current use61 ± 17 (56)58 ± 18 (51)
 Never used71 ± 16 (21)66 ± 16 (20)
 Ever used61 ± 17 (65)58 ± 18 (60)
 Discontinued61 ± 15 (9)58 ± 21 (9)

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

This article describes the development and measurement of psychometric properties of SMILEY using rigorous methods of reliability and validity testing. SMILEY is a novel, brief, valid, reliable, easy to administer and score SLE-specific pediatric HRQOL scale with parallel child and parent reports. SMILEY is suitable for use across different age groups and literacy levels, as we have demonstrated the ease with which it is understood; subjects were able to complete SMILEY independently with very few items left blank. SMILEY may ultimately prove itself to be a useful adjunct to clinical practice and research, providing valuable insight to the impact of SLE on the overall QOL of the child.

Moderate agreement was found between child and parent reports, which is also consistent with previous studies (9). SMILEY emphasizes the child's subjective perceptions in the context of SLE. Although it is ideal for children to evaluate their own QOL, there are limitations such as unreliable or invalid results based on their varying degrees of long-term perspective, memory, age, and communication skills (31). Central nervous system involvement in varying degrees, described in more than half of children with SLE, may affect their responses. Parents' reports are indispensable in these cases and their perception affects children's health care utilization (16). In this study, parents' SMILEY scores were lower compared with children's scores, indicating that parents may experience a greater burden of SLE, which may stem from their greater awareness of the disruption in the child's life and anxiety about the future. Parental expectations, feelings of guilt, health, mental status, QOL, and values may influence their reports and lead them to perceive their child's QOL as being poor (31). The level of parent-child agreement varies and is dependent on the measurement method, domains studied, and children's/parents' physical and mental health status (3, 32–34). The observed moderate correlation between the child and parent reports further supports the need for parallel child and parent reports to obtain both perspectives (15, 16).

Consistent with previous studies, only mild correlations were found between the limitation domain scores of the child SMILEY report and the SLEDAI, PGA, or SDI (9, 27–29). Given the heavy emphasis of SLE activity and damage on the more easily quantifiable manifestations of SLE, such as serologic tests and clinical signs, it is likely that these measures correlate with physical aspects of QOL (9, 27, 35). Lack of a significant correlation of increased disease duration with QOL may be attributable to the response shift phenomenon (36).

We found a greater correlation of QOL with patient-perceived SLE status than with SLEDAI/PGA as assessed by the physician. Physician and patient/parent assessments of disease activity and QOL are often dependent on different factors and therefore may not be closely related (37–40). These results emphasize the importance of recognizing QOL and SLE-related measures such as activity, damage, and duration as distinct concepts, with varying levels of connectedness and dynamic interaction (9). Combining child, parent, and physician reports may provide the most reliable and comprehensive assessment of the impact of SLE on children's QOL.

SMILEY demonstrated good discriminative properties, as scores decreased going from low to high disease activity, damage, and immunomodulating medication use. Increased disease activity, damage, and use of chemotherapeutic agents often cause limitation of activities and fatigue. Therefore, it is not surprising to see a greater discriminatory trend in the limitation domain. An increase in sample size will likely result in significant discrimination in other domains. Because of our small sample size relative to the number of variables, we did not perform factor analysis or multidimensional scaling.

The study population comprised mainly teenage school-attending girls from working middle-class families, with low disease activity and disability followed at tertiary care centers, which may limit generalizability. Despite this selection bias, the population was well distributed in terms of age, sex, geography, ethnicity, socioeconomic status, and insurance status.

Some of the limitations in this study were unavoidable. There is a risk of children and guardians conferring with each other while completing the questionnaires at home when evaluating test–retest reliability. Completion of the questionnaires may be influenced by the nature of the clinical visit and/or hospital stay. This bias cannot be resolved, but is a common denominator for all subjects. Because subjects may skip questions, we reviewed the questionnaires for missing and inconsistent data and asked the subjects to complete the questions. There are limitations when using the Likert scale for responses, such as end-aversion and positive skew bias. We are recruiting additional subjects to examine the prevalence of these biases. Currently, we are evaluating the responsiveness of SMILEY to change in disease activity and planning prospective studies of cross-cultural adaptation and validation in different countries.

SMILEY has several advantages over other generic QOL instruments when considering its utility for children with SLE. SMILEY is a brief, valid, and reliable SLE-specific pediatric HRQOL scale with parallel child and parent reports that is easy to comprehend, administer, and score. Because SMILEY is derived from the attitudes and feelings of children with SLE and their parents, it is most relevant for children with SLE. SMILEY directs the subject to focus on SLE, and therefore assesses the self-perceived impact of SLE on HRQOL with maximum possible accuracy. This feature is useful for evaluating response to clinical treatment, thereby making SMILEY a valuable adjunct to clinical practice and outcomes research.

AUTHOR CONTRIBUTIONS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

Dr. Moorthy had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study design. Moorthy, Peterson, Harrison, Lehman.

Acquisition of data. Moorthy, Baratelli, Onel, Chalom, Haines, Hashkes, Lehman.

Analysis and interpretation of data. Moorthy, Peterson, Harrison.

Manuscript preparation. Moorthy, Peterson, Harrison, Hashkes, Lehman.

Statistical analysis. Moorthy, Peterson.

ROLE OF THE STUDY SPONSOR

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

Pfizer supported Dr. Moorthy's work through a peer reviewed Clinical Scholar grant. They were not involved in the study design, data collection, or the analysis and interpretation of the data, and had no influence on the publishing on the data.

Acknowledgements

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information

We thank the following individuals for collaborating and helping with the project: Daniel Notterman and Afton Hassett (Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ) Mary Charlson and Carol A. Mancuso (Cornell University, New York, NY), Laura Robbins and Steve Paget (Hospital For Special Surgery, New York, NY), and John Allegrante (Columbia University, New York, NY) for support and encouragement for the project and feedback; Alexa Adams, Lilliana Barillas, Emma McDermott, and Sheila Angeles (Hospital For Special Surgery, New York, NY), Laura Barinstein (Maimonedes Medical Center, Brooklyn, NY), and Liza Vazquez (Hospital Espanol Auxilio Mutuo, San Juan, Puerto Rico) for identifying subjects for recruitment at Hospital for Special Surgery and completing SLE status measures; Charles Spencer and Linda Wagner-Weiner (La Rabida Childrens Hospital, Chicago, IL) for encouraging their patients to participate in the study; Elizabeth Levey (La Rabida Childrens Hospital, Chicago, IL) for helping with patient recruitment; and Bettina Eulie (St. Barnabus Medical Center, Livingston, NJ), Doreen Tabussi (Hackensack University Medical Center, Hackensack, NJ), Deborah Bork (Cleveland Clinic Foundation, Cleveland, OH) for helping with patient identification and recruitment, and Krithika McPherson for her editing skills.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information
  • 1
    Gutierrez-Suarez R, Ruperto N, Gastaldi R, Pistorio A, Felici E, Burgos-Vargas R, et al, for Paediatric Rheumatology International Trials Organization (PRINTO). A proposal for a pediatric version of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index based on the analysis of 1,015 patients with juvenile-onset systemic lupus erythematosus. Arthritis Rheum 2006; 54: 298996.
  • 2
    Ruperto N, Ravelli A, Cuttica R, Espada G, Ozen S, Porras O, et al, for the Paediatric Rheumatology International Trials Organization (PRINTO) and the Pediatric Rheumatology Collaborative Study Group (PRCSG). The Pediatric Rheumatology International Trials Organization criteria for the evaluation of response to therapy in juvenile systemic lupus erythematosus: prospective validation of the disease activity core set. Arthritis Rheum 2005; 52: 285464.
  • 3
    Eiser C, Morse R. Can parents rate their child's health-related quality of life? Results of a systematic review [review]. Qual Life Res 2001; 10: 34757.
  • 4
    Moorthy LN, Peterson MG, Onel KB, Harrison MJ, Lehman TJ. Quality of life in children with systemic lupus erythematosus [review]. Curr Rheumatol Rep 2005; 7: 44752.
  • 5
    Moorthy LN, Harrison MJ, Peterson M, Onel KB, Lehman TJ. Quality of life in children with systemic lupus erythematosus: the search for appropriate measurement tools [review]. Pediatr Rheumatol Online J [serial online]. 2004; 2(2). URL: http://www.pedrheumonlinejournal.org/march-april/moorthy1.htm.
  • 6
    Eiser C, Morse R. Quality-of-life measures in chronic diseases of childhood. Health Technol Assess 2001; 5: 1157.
  • 7
    Varni J, Seid M, Rode CA. The PedsQL: measurement model for the pediatric quality of life inventory. Med Care 1999; 37: 12639.
  • 8
    Duffy CM. Measurement of health status, functional status, and quality of life in children with juvenile idiopathic arthritis: clinical science for the pediatrician. Pediatr Clin North Am 2005; 52: 35972.
  • 9
    Moorthy LN, Harrison MJ, Peterson M, Onel KB, Lehman TJ. Relationship of quality of life and physical function measures with disease activity in children with systemic lupus erythematosus. Lupus 2005; 14: 2807.
  • 10
    Moorthy LN, Peterson MG, Harrison MJ, Onel KB, Mohan DR, Lehman T. Relationship of school attendance with quality of life, physical function, disease activity and damage in pediatric systemic lupus erythematosus [abstract]. Proceedings of the 2005 FOCIS conference; 2005 May 12–16; Boston, Massachusetts.
  • 11
    Moorthy LN, Harrison M, Peterson M, Onel K, Lehman T. Simple Measure of the Impact of Lupus Erythematosus in Youngsters (SMILEY): examination of psychometric properties [abstract]. Arthritis Rheum 2003; 48 Suppl 9: S687.
  • 12
    Moorthy LN, Robbins L, Harrison MJ, Peterson MG, Cox N, Onel KB, et al. Quality of life in paediatric lupus. Lupus 2004; 13: 23440.
  • 13
    Moorthy LN, Peterson MG, Onel KB, Baratelli M, Haines K, Tabussi D, et al. Multicenter Validation Of Simple Measure Of Impact Of Lupus Erythematosus In Youngsters—a new quality of life measure in pediatric lupus [abstract]. Ann Rheum Dis 2006; 65 Suppl II: 446.
  • 14
    Moorthy LN, Peterson MG, Baratelli M, Adams A, Barillas L, McDermott E, et al. Simple Measure Of The Impact Of Lupus Erythematosus In Youngsters (SMILEY): validity, internal consistency and test-retest reliability [abstract]. Arthritis Rheum 2006; 54 Suppl 9: S162.
  • 15
    Varni JW, Seid M, Smith Knight T, Burwinkle T, Brown J, Szer IS. The PedsQL in pediatric rheumatology: reliability, validity, and responsiveness of the Pediatric Quality of Life Inventory Generic Core Scales and Rheumatology Module. Arthritis Rheum 2002; 46: 71425.
  • 16
    Varni J, Seid M, Kurtin PS. PedsQL 4.0: reliability and validity of the Pediatric Quality of Life Inventory version 4.0 generic core scales in healthy and patient populations. Med Care 2001; 39: 80012.
  • 17
    Singh G, Athreya BH, Fries JF, Goldsmith DP. Measurement of health status in children with juvenile rheumatoid arthritis. Arthritis Rheum 1994; 37: 17619.
  • 18
    Ruperto N, Ravelli A, Pistorio A, Malattia C, Cavuto S, Gado-West L, et al, for the Paediatric Rheumatology International Trials Organisation. Cross-cultural adaptation and psychometric evaluation of the Childhood Health Assessment Questionnaire (C-HAQ) and the Child Health Questionnaire (CHQ) in 32 countries: review of the general methodology. Clin Exp Rheumatol 2001; 19 Suppl 23: S19.
  • 19
    Piers EV, Harris DB. Piers-Harris Children's Self Concept Scale. In: The seventh mental measurements yearbook. Vol. I. Highland Park (NJ): Gryphon Press; 1972.
  • 20
    Piers EV, Harris DB. Piers-Harris Children's Self Concept Scale (PHCSCS). Nashville (TN): Western Psychological Services; 1969.
  • 21
    Petri M, Hellmann D, Hochberg M. Validity and reliability of lupus activity measures in the routine clinic setting. J Rheumatol 1992; 19: 539.
  • 22
    Bombardier C, Gladman DD, Urowitz MB, Caron D, Chang CH, and the Committee on Prognosis Studies in SLE. Derivation of the SLEDAI: a disease activity index for lupus patients. Arthritis Rheum 1992; 35: 63040.
  • 23
    Gladman D, Ginzler E, Goldsmith C, Fortin P, Liang M, Urowitz M, et al. The development and initial validation of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index for systemic lupus erythematosus. Arthritis Rheum 1996; 39: 3639.
  • 24
    Ravelli A, Duarte-Salazar C, Buratti S, Reiff A, Bernstein B, Maldonado-Velazquez MR, et al. Assessment of damage in juvenile-onset systemic lupus erythematosus: a multicenter cohort study. Arthritis Rheum 2003; 49: 5017.
  • 25
    Rood MJ, ten Cate R, van Suijlekom-Smit LW, den Ouden EJ, Ouwerkerk FE, Breedveld FC, et al. Childhood-onset systemic lupus erythematosus: clinical presentation and prognosis in 31 patients. Scand J Rheumatol 1999; 28: 2226.
  • 26
    Streiner DL, Norman GR. Health measurement scales: a practical guide to their development and use. 3rd ed. New York: Oxford University Press; 2003.
  • 27
    Jolly M, Utset TO. Can disease specific measures for systemic lupus erythematosus predict patients health related quality of life? Lupus 2004; 13: 9246.
  • 28
    Hanly JG. Disease activity, cumulative damage and quality of life in systemic lupus erythematosus: results of a cross-sectional study. Lupus 1997; 6: 2437.
  • 29
    Gladman DD, Urowitz MB, Ong A, Gough J, MacKinnon A. Lack of correlation among the 3 outcomes describing SLE: disease activity, damage and quality of life. Clin Exp Rheumatol 1996; 14: 3058.
  • 30
    Gomez D, Correa PA, Gomez LM, Cadena J, Molina JF, Anaya JM. Th1/Th2 cytokines in patients with systemic lupus erythematosus: is tumor necrosis factor α protective? Semin Arthritis Rheum 2004; 33: 40413.
  • 31
    Vogels T, Verrips GH, Verloove-Vanhorick SP, Fekkes M, Kamphuis RP, Koopman HM, et al. Measuring health-related quality of life in children: the development of the TACQOL parent form. Qual Life Res 1998; 7: 45765.
  • 32
    Brunner HI, Klein-Gitelman MS, Miller MJ, Trombley M, Baldwin N, Kress A, et al. Health of children with chronic arthritis: relationship of different measures and the quality of parent proxy reporting. Arthritis Rheum 2004; 51: 76373.
  • 33
    Loonen HJ, Derkx BH, Koopman HM, Heymans HS. Are parents able to rate the symptoms and quality of life of their offspring with IBD? Inflamm Bowel Dis 2002; 8: 2706.
  • 34
    Sung L, Young NL, Greenberg ML, McLimont M, Samanta T, Wong J, et al. Health-related quality of life (HRQL) scores reported from parents and their children with chronic illness differed depending on utility elicitation method. J Clin Epidemiol 2004; 57: 11616.
  • 35
    Khanna S, Pal H, Pandey RM, Handa R. The relationship between disease activity and quality of life in systemic lupus erythematosus. Rheumatology (Oxford) 2004; 43: 153640.
  • 36
    Hagedoorn M, Sneeuw KC, Aaronson NK. Changes in physical functioning and quality of life in patients with cancer: response shift and relative evaluation of one's condition. J Clin Epidemiol 2002; 55: 17683.
  • 37
    Ravelli A, Viola S, Ruperto N, Corsi B, Ballardini G, Martini A. Correlation between conventional disease activity measures in juvenile chronic arthritis. Ann Rheum Dis 1997; 56: 197200.
  • 38
    Mack JW, Hilden JM, Watterson J, Moore C, Turner B, Grier HE, et al. Parent and physician perspectives on quality of care at the end of life in children with cancer. J Clin Oncol 2005; 23: 915561.
  • 39
    Furlong W, Barr RD. Proxy assessment of quality of life in pediatric clinical trials: application of the Health Utilities Index 3 [letter]. Qual Life Res 2006; 15: 12913; discussion 1295–6.
  • 40
    Cox CL, Lensing S, Rai SN, Hinds P, Burghen E, Pui CH. Proxy assessment of quality of life in pediatric clinical trials: application of the Health Utilities Index 3. Qual Life Res 2005; 14: 104556.

Supporting Information

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. AUTHOR CONTRIBUTIONS
  8. ROLE OF THE STUDY SPONSOR
  9. Acknowledgements
  10. REFERENCES
  11. Supporting Information
FilenameFormatSizeDescription
ACR06-048922988.pdf343KSupporting Information file ACR06-048922988.pdf

Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.